The manual versions of the E200 CDI, E220 CDI and E250 CDI diesels all return 53mpg and have tax-friendly CO2 figures of less than 140g/km.

The E300 Hybrid is the latest in the line of diesel hybrids launched.

At the heart of it is a 27bhp electric motor (powered by a 19kw lithium-ion battery) connected to the firm’s 7G-Tronic automatic transmission.

The combustion side of the set-up is provided by the well-proven 201 bhp 2.1 litre 4-cylinder common-rail turbo diesel engine found in the E250.

Thanks to the use of a wet clutch, the 7G-Tronic automatic gearbox can disconnect drive from the diesel motor, enabling the car to run in pure electric mode up to 21 mph for one kilometer; and at higher cruising speeds where there is less demand for power, such as going downhill.

Available in saloon or estate guise, there’s nothing apart from the badge to visually separate this hybrid model from its conventionally powered siblings.

The current E-Class has a distinctly traditional three-box saloon shape, harking back several generations to the iconic W124 series.

Strangely, despite the estate being of sleeker appearance, it’s the saloon that boasts better aerodynamics; with a drag coefficient of 0.26.

Like all modern Mercedes, safety is order of the day, and along with a full quota of seven airbags, the E300 Hybrid comes with a plethora of both active and passive safety innovations.

PRE-SAFE® anticipatory safety system prepares the occupants and the car for an imminent collision, so that the seat belts and the airbags can deploy with maximum effect in the event of an impact.

Every time you buckle up for a journey, PRE-SAFE® makes its present felt by tightening any slack in the belt. To help keep drivers awake and aware, there’s Attention Assist, which monitors steering behavior for signs of deviation as a result of fatigue.

Visual and audible alerts are then made to alert the driver to take a break.

E-Class is also one of the few cars available with advanced protection for pedestrians: Active Bonnet – pedestrian safety detects an impact and raises the bonnet by 50 mm, creating an additional crumple zone.

IN THE CABIN: The first impression of the E-class’s cabin is of understated opulence. It’s comfy, classy and well made.

Although not as lavishly equipped as some Japanese offerings, the sense of occasion and presence of the Merc’s interior is leagues apart.

In true Mercedes tradition, the optional equipment list is distinctly longer than the standard one.

That being said, standard kit levels are far from miserly.

Along with wood and leather, you get individually adjustable two-zone climate control, cruise control with Speedtronic variable speed limiter, front and rear parking and maneuvering aid, a tyre pressure loss warning system and integrated infotainment navigation system with Bluetooth hands-free telephony.

Other nice touches include snazzy dimmer controlled ambient lighting in

the dash and door panels and auto-dimming mirrors to prevent glare.

Thanks to the E-Class’s dimensions, there’s an abundance of space for five adult occupants, along with a useful array of storage areas. The enormous 540-litre boot has good access and features luggage securing hooks and load nets.

It is disappointing to therefore note that a 60/40 split rear bench is an expensive option.

ON THE ROAD: It’s easy to get comfortable behind the wheel of the E300 Hybrid, as it is in all E-Class models.

Driving position is spot-on, with both front seats offering good levels of adjustability – even more so if you plump for the optional £1,225.00 memory package.

Manoeuvring of the vehicle is easy; thanks to light controls and good all-round visibility, although when rear window is wet over-the shoulder vision can become obstructed in the saloon.

For drivers used to diesel and petrol engines, the first journey in the E300 Hybrid can cause a few surprises, as the car moves off virtually silently under full electric power until 22 mph.

A heavy prod of the accelerator also causes the 2.1 litre diesel motor to burst into life to assist with acceleration. The combined efforts of diesel and electric motors means that progress can be very swift when required.

Response for a hybrid system is satisfyingly quick and direct, with only the absence of a meaty soundtrack likely to disappoint keener drivers.

The metallic thrum of a 4-cyclinder diesel engine isn’t ever going to be an aural treat, but this is compensated by high levels of refinement coupled with almost sport saloon performance.

Thanks to the combined peak power of 201bhp and 435lb ft of combined torque, E300 Hybrid can hit 62 mph in 7.5seconds and push on to 150 mph.

The rest of the drive impresses too. Steering is nicely weighted, and direct enough for a car weighing nearly two tonnes and the well-damped suspension does an effective job of ironing out road surface imperfections.